A “multi-tool” with several features in addition to small knife fell within the list of prohibited weapons for purposes of Welfare and Institutions Code section 626.10, subdivsion (a). In an appeal from his conviction for possession of a weapon on school grounds, the minor claimed the “multi-tool” he possessed did not fall within the weapons prohibited by section 626.10, subdivision (a). He contended that the “multi-tool” was not a knife with a blade that locks into place, and is not a knife because it contains multiple tools, only one of which is a small awkward blade. The appellate court rejected the argument, finding that functionally, the “multi-tool” is a folding knife with a blade that locks into place. The statute does not require a particular size, sharpness, or ease of deployment. The Legislature wished to protect against the danger of knives with concealed blades regardless of size or relative capability for inflicting bodily damage. The conglomeration of other tools did not mean the product is no longer a knife.